Marta Capellas, food research from Universitat Autònoma de Barcelona, unveiled the results at the Free From Foods Expo last week.
Attempting the combat common gluten-free problems such as nutrition, shelf-life, convenience, clean label and cost, Capellas and her team investigated using different flours in bread making to create the perfect gluten-free loaf.
The team trialled different formulation and technology techniques at their food processing plant in Barcelona.
Gluten is the main structural forming protein of most basked products and contributes to the product’s elasticity, mouthfeel and shelf-life.
The gluten-free trend has been growing extremely fast over the last ten years, with more and more consumers buying into the trend according to Mintel.
Legume flours
First up, Capellas measured the effects of different legume flours on baking characteristics, including shelf life and volume, of gluten-free bread.
The flours tested were chickpea, pea isolate, soya and carob germ.
The shelf life was measured by the hardness of the bread on day five.
Chickpea flour was found to increase the volume of the bread the most and also indicated to have the longest shelf life, however only 17% of consumers preferred this bread.
Carob germ produced the hardest bread on day five, revealing a short shelf life.
A consumer test was carried out with 66 volunteers between the ages of 20 and 60. All were regular bread consumers and all tried each formulation and were asked to indicate the most and the least preferred sample.
Capellas found that all breads made with legume flours showed good physico-chemical characteristics and “an adequate sensory profile”.
However, the results indicated that chickpea flour and pea isolate flours could be suitable alternatives for gluten-free breads due to their performance across all measurements evaluated.
Tiger nut derived products
Tiger nut, a non-allergenic tuber rich in carbohydrates, fat, fibre, minerals and vitamins C and E, was also tested for its effects when used in gluten-free bread.
Tiger nut milk, tiger nut flour and tiger nut byproduct were all evaluated in the same way as the legume flours, and were compared against soya.
In this study, tiger nut milk came out on top with 61% of participants saying it was their preferred choice, as well as producing the biggest volume and longest shelf life.
Capellas says the milk gave the bread a natural sweetness and thus would be suitable for gluten-free brioche.
This was compared to tiger nut byproduct,, which only 2% of the participants preferred and also had the lowest volume and shelf life.
Tiger nut flour performed on par with soya in terms of consumer preference and volume, but indicated a longer shelf life.
Capellas commented that the use of a mix of chickpea and tiger nut flours gave a cleaner label, less fat and a better nutritional profile than most gluten-free breads.
Chestnut flour and chestnut flour sourdough
With an objective to study spontaneously fermented chestnut flour sourdough and its effect in gluten-free bread, Capellas conducted another study.
In this, chestnut flour sourdough was compared to chestnut flour and corn starch.
The chestnut flour sourdough was fermented for five days before being used in bread.
Chestnut was used due to its nutritional and health benefits, as it contains a high amount of protein, fibre, as well as minerals and vitamins B, E, K, P and Mg.
Loaf colour, bake loss, water activity, crust and crumb colour, and crumb texture were evaluated for all samples.
Chestnut flour sourdough was found to have increased fibre and an increased mineral diversity however it did not prove to be as popular with consumers as chestnut flour bread.
The volume also decreased when chestnut flour sourdough was used, but did show an improved shelf life.
Capellas hypothesises that chestnut flour sourdough was not popular with consumers “probably due to the reduction in the characteristic sweet taste of chestnut flour caused by sourdough fermentation”.